Total knee joint replacement surgery is now a common tool in the orthopedic surgeon's repertoire. However, there is a present controversy as to whether during a knee joint replacement surgery, the patella should be replaced as well. Some practitioners will replace the patella as well during the surgery if it is particularly worn. Other practitioners prefer to avoid replacing the patella at all costs. The controversy is difficult to resolve, because the patella replacement portion of a total knee replacement operation is the most poorly performed and understood aspect of the surgery. The standard full knee replacement surgery typically will balance the flexion gap and the extension gaps, but pay less attention to or overlook the patello-femoral gap.
The reason for this is at least in part because of the lack of appropriate alternative patellar jigs to guide the surgeon when replacing/resurfacing the patella. Typically, the patella is cut in isolation, i.e., separate and away from the femoral and tibial components of the replacement knee prosthesis. Because the patella is cut/resurfaced in isolation, it is difficult to easily assure the accuracy of the cutting/resurfacing of the patella to accommodate the flexion gap, the extension gap and the patello-femoral gap at the replacement knee joint.
It would be beneficial to the field to have an alternative patella jig that can not only be used in situ, but which also enables cutting of the patella with physical reference to the femoral prosthetic (or trial) component that it is to interface with. Additionally, it would be beneficial to have such alternative patella jig that can hold a range of patella sizes, without compromising accuracy of the physical interface alignment.